1. Field of the Invention
This invention relates to the installation of monolithic refractory linings in process vessels or equipment such as reactors, conduits, furnaces, incinerators and the like and more particularly to an improved anchor which is inexpensive to form and install which not only secures the refractory lining in place but also provides protection of the refractory from mechanical erosion.
2. Description of the Prior Art
Refractory liners have been used for many years in process vessels, reactors, conduits, furnaces and the like to provide thermal insulation and in environments such as fluidized catalytic reactors or regenerators or stacks to provide resistance to abrasion or erosion. Thus such liners can serve not only to thermally insulate a shell or other surface but also to prolong its service life by shielding it from erosion by abrasion. In fluid catalytic cracking units for petroleum hydrocarbons quite high fluid velocities which may be on the order of 50 to 70 ft/second occur and the abrasive effect of entrained cracking catalyst is very pronounced. Moreover, high temperatures are involved, for example in the regenerator the temperature of gases exiting through the cyclones may be on the order of 1250.degree.-1350.degree. F. and in the reactor the temperature may be 800.degree.-900.degree. F. Accordingly, the usual practice has been to line all vessels, conduits and cyclone separators through which fluid with entrained catalyst flows with refractory liner to prevent erosion of the metal surfaces and to provide thermal insulation. To retain the refractory which may be a refractory cement, a concrete cement-aggregate mixture, a reinforced cement or concrete, various anchoring arrangements have been employed. U.S. Pat. No. 3,076,481 to Wygant, which is hereby incorporated by reference, contains a description of certain of the problems involved in anchoring refractory concrete linings and of a particular anchorage arrangement.
Heretofore, a preferred anchorage arrangement which also provided erosion protection was the use of hexagonal steel grating which was welded to the vessel or conduit wall. The grating had the same depth as the refractory liner to be applied and the refractory was deposited in the hexagonal spaces defined by the grating. Thus the grating provided the desired erosion resistance for the refractory by projecting to the exposed surface of the refractory. The disadvantages of hexagonal grating are its relatively high cost, lack of flexibility which makes it difficult or impossible to apply to curved surfaces, its tendency to separate from the vessel or conduit wall over relatively large areas when welds fail and its unsuitability for use with fiber reinforced refractories or with refractory concretes containing coarse aggregate particles.
In situations where hexagonal grating is not suitable weldable studs such as those described in U.S. Pat. No. 3,657,851 to Chambers et al. and U.S. Pat. No. 3,336,712 to Bartley have been proposed. Such studs are suitable for use with fiber reinforced refractory or with refractory concrete but do not provide erosion protection for the refractory.
One object of this invention is to provide an inexpensive anchoring arrangement suitable for use with fiber or needle reinforced refractory cement or concrete and which provides protection of the refractory from erosion.
A second object is to provide an anchor arrangement which may be utilized on relatively highly curved surfaces such as within cyclones or conduits such as riser reactors or transfer lines.
A further object is to provide an anchor which is appropriately shaped that it may be installed in an array with other like anchors to provide erosion protection from streams in any direction.
Other objects and advantages of this invention will become apparent to one skilled in the art based upon the ensuing description.